Science is Magic

49

Once the can is balanced,

give the rim a gentle tap.

The can will spin around

without falling, making the

trick even more impressive.

4

Try to balance the can

on its edge. If it falls

over, pour out some

of the water. If it falls

back to an upright

position, add more

water into the can.

3

This trick works because of something

called the center of mass.

This is the central point of an object’s total weight, and

where it is perfectly balanced. By changing the amount

of water in the can, you move the center of mass until

it’s at the exact place where the can will balance.

When the can is full and

tilted on its edge, the

center of mass is roughly

in the middle of the can

and not above the edge,

so it topples over.

CENTER OF MASS

When you take some of

the water out of the can,

the center of mass shifts

across because the weight

inside has moved. If you

can get the center of mass

above the edge of the can,

it will balance.

T

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C

AN

W

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P
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!
SCIENCE
PART...
THE
US_048-049_Balancing_soda_can.indd 49 12/09/2018 15:49